Antenna system



p 10, 1940- L. G. CUMMING 2,214,102 7 ANTENNA SYSTEM Original Filed May 27, 1938 Sheets-She et l V ENTOR? Q; Gvt vWMM/v g G M ATTORNEY.

Sept. 10, 1940. 1.. cs. CUMMING ANTENNA SYSTEM Original Filed May 27, 1938. 2 Sheets-Sheet 2 IN VEN TOR.

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ATTORNEY Patented Sept. 10, 1940 ANTENNA SYSTEM Laurence G. Cumming,

Boston, Mass, assignor of one-half to Edmund (3. Mayo, Providence,

ill.

Griginal application May 27, 1938, Serial No.

210,475. Divided and 1939, Serial No. 274,255

13 Claims.

My invention relates broadly to radio signal systems and more particularly to an antenna structure for use in cooperation with radio signalling apparatus in public service boxes.

This application is a division of my application Serial No. 210,475, filed May 2'7, 1938, for Radio call box system.

One of the objects of my invention is to provide an arrangement of antenna structure adapted to be mounted in association with public service boxes equipped with radio signalling apparatus for directively transmitting radio signals to a central station with minimum mutual interference.

Another object of my invention is to provide a construction of antenna system for use in association with public service boxes in a municipal radio protection system by which radio energy may be directively propagated from various positions throughout a community to a central station with no appreciable interference between simultaneously operating transmitters.

Still another object of my invention is to provide a construction of antenna system for use in association with call box transmitters in a radio protection system for communities in which the spacial relation of a transmitting antenna with respect to a parasitic reflector may be selectively fixed at each public service box for effecting transmission of the signalling energy to a central station with inappreciable interference with respect to other public service box radio transmitters throughout the community.

A further object of my invention is to provide a construction of transmitting and receiving antenna for radio transmitting and receiving apparatus in public service boxes and in which the receiving antenna also operates as a reflector for the directive transmission of signals from the transmitting antenna.

Other and further objects of my invention reside in the method of coupling a radio transmitter in a public service call box with an antenna and electrically connecting a radio receiving system with a parasitic antenna or reflector as set forth more fully in the specification hereinafter following by reference to the accompanying drawings, in which:

Figure 1 is a front elevation of a public service box, signal light and pedestal mounting illustrating the antenna structure of my invention arranged thereon; Fig. 2 is a side elevation of the public service box, signal light, antenna structure and pedestal mounting shown in Fig. 1;

" Fig. 3 is a front elevation of the antenna of my this application May 17,

invention mounted on the pedestal extending from the public service box, with parts broken away and illustrated partially in cross section showing the relationship of the transmitting antenna and the parasitic reflector or receiving antenna; Fig. 4 is a cross sectional view taken on line lll of Fig. 3; Fig. 5 illustrates the manner of establishing coupling relationship between the connection to the antenna and the antenna connection extending from the radio transmitter within the public service box; and Fig. 6 is an enlarged cross sectional view illustrating more clearly the coaction between the connection extending from the transmitting antenna and the lead which connects to the radio transmitter in the public service box.

The antenna system of my invention is particularly adapted for use in public service communication systems set forth more fully in application 210A75, filed May 2'7, 1938, for Radio call box system, of which this application is a division. The antenna system of my invention is mounted above the call light on the pedestal extending from the public service box which is generally located at the corners of street or highway intersections. The radio transmitting and receiving apparatus which is mounted within the radio box supported on the aforesaid pedestal cooperates with radio transmitting and receiving apparatus and a central station. The antenna system associated with the radio box is so designed that signals may be directively propagated from the radio box to the central station with inappreciable interference with respect to similar installations at other positions in the community. The antenna system consists of a one-quarter wave vertical antenna adjustably supported on a substantially horizontal mounting which also provides a support for a parasitic reflector arranged in spaced relation to the vertical antenna. The parasitic reflector is adjustable in spacial relation to the vertical antenna and is located at any point up to three--eighths wave lengths with respect to the vertical antenna. The vertical antenna and parasitic reflector are carried on tubular members which telescope into a substantially horizontal tubular support mounted above the call light. Adjustable locking means are provided for selectively fixing the antenna and parasitic reflector in predetermined spacial relation when moved to adjusted position. The antenna-parasitic reflector assembly is adjustable throughout 360 for effectively utilizing the directional characteristics of the assembly in transmission and reception of signalling energy to and from a central station. The antennaparasitic reflector assembly may be locked in position when adjusted by a collar and set screw device operative with respect to the supporting pedestal above the call light. The direction of propagation of the signalling energy with respect to the central station may therefore befixed with precision so that transmitters at adjacent street intersections cause a minimum of mutual 7 interference at the central station.

In order to render the radio call box equipment universal in character and capable of being readily installed in various locations about a central station, the antenna structure is capable of being angularly adjusted in position on the support above the call box as heretofore described. Moreover, the antenna structure is equipped with an emitting portion and a reflecting portion capable of adjustable spacial relation one with respect to the other. Because of the many differences in directional characteristics encountered in installations embodying my invention, the antenna structure must be capable of different angular arrangement in various planes so that I provide for the adjustment of the antenna structure in different angular positions with respect to the vertical as well as various positions with respect to the transverse spacial relation of the emitting portion with respect to the reflecting portion. Such changes in angular position are particularly valuable where obstructions to the radiation of high frequency energy may occur. The antenna reflector type of radiation system which I employ is depended upon to reduce interference on the same or contiguous frequencies when a plurality of stations are used. The adjustable arrangement of the antenna structure of my invention is advantageous in arranging the antennas on difierent call boxes in various divisions to coact with a central station without mutual interference. One call box station has negligible efiect upon another call box station for the antenna arrangement at each call box station is so devised as to emit the high requency energy in that plane of polarization which will be received at the central station irrespective of energy being simultaneously emitted from other call box stations in the about the central station. I am not unmindful of the problems which arise in multiple systems of transmission wherein a number of permutations and combinations of transmitter may occur at the same frequency for signals transmitted to the same central station, whether the system be for purposes of fire, police, general communication, traffic control, marine, aviation or mobile systems generally. However, the central station may be readily equipped with directional receiving means capable of discriminating against signals in certain areas while allowing reinforced reception of signals in other areas and consequent increase in signal to noise ratio. Moreover, I contemplate in my system the employment of sequence transmission in cases of emergency so that an authorized agent at any one of the call boxes may be informed from a central station to stand by pending the clearance of an emergency call or priority message from some other call box station.

Referring to the drawings in detail, the numeral (i2 designates a pedestal projecting above the box Eli and carrying at its top a. cylindrical glass prism 63 which encloses a suitable call light or lighting means contained within the prism 63. The box 2% houses the radio transmitting and receiving apparatus and control circuits therefor. The apparatus may connect by cables extending through pedestal 6'2 to suitable battery or other power source as. indicated by housing 35 to the antenna structure '54, 8?. The citizens control switch for operating the radio box is indicated at S2 extending from radio box it. Above the prism 63 there is a circular cap 6d carrying a clamp 55, the clamp 65 being adjustable in selected angular position throughout a range of 360 by means of screw device ii-l. Firmly connected to the clamp 65, I provide a tubular antenna arm ii'i forming a frame for mounting the antenna structure.

The screw ilii permits the entire frame carrying the tubular antenna arm to be selectively adjusted in position. The ends of the arm fill are provided with taper threads 68 and slots till therein, permitting the nuts 'Hi to grip very tightly for securing the extension members ii and $5 in selected positions. The extension member H has its one end if? fitting into arm ill and its other end '53 bent at substantially right angles with respect to the end l2. Projecting upwardly from the end "53 of the extension ii and protected therefrom by insulating grommet or bushing '55 there is a transmitting antenna ft. The grommet or bushing 75 serves as an insulated support for the antenna "i i. The antenna E lis held firmly in place by virtue of pressure exerted upon the mounting means 75 by the screw '65 through the grommet or bushing 15.

The numeral ll designates a conduit having its outer end '58 fitting into the ends '52 of the tubular extension ll. The conduit 'l'l passes through but is spaced away from the inner walls of arm 67 and emerges from the arm through opening 239' and projects downwardly through the prism 53.

An electrical connection iii passes through ccnduit ill and tubular extension ii and connects with antenna M as shown. Arranged on the downwardly projecting end of the tube ll, I provide a plug member 88. A detachable connection is provided at 82 for interconnecting sleeve 32a disposed in insulated relation within socket member 83 as shown. A connecting wire B l extends from sleeve 82a in socket member 33 through. a suitable conduit to the transmitter in the call box 2t.

Arranged in the end of the arm 6'! opposite that end containing the transmitting antenna there is another extension tube designated at 85. Extension tube 85 is disposed in a substantially horizontal plane in alignment with extension ll. Extension tube 85 is provided at its extremity with an upwardly extending end 86 carrying a parasitic or power fed reflector 31, said reflector being separated from said extension tube 85 by means of insulating grommet or bushing 88. The insulating grommet or bushing 88 is held firmly in place by means of pressure exerted by set screw 88 upon grommet 88. The reflector is shown at 8'! in parallel alignment with the antenna M. The reflector 8'! is connected through a cable i3? which may extend in a conduit similar to conduit ll through arm fill and through the call light housing to the equipment within the call box 20. For purposes of explaining my invention, I have merely indicated the connecting cable 531 in Fig. 3. It will be understood that cable I t? is well insulated from the structure of the pedestal mounting and that a detachable coupling similar to the couplings 80, 83, heretofore described, may be employed in establishing connection with the equipment within box 20. It will be understood that the couplings indicated generally as pin and socket connections 88 and 83 are well insulated from the structure of pedestal support and maintain a high degree of electrical efliciency, allowing the use of reflector 8! as a receiving antenna if desired independently of its use in coaction with the directive antenna 14 during transmission. Because of the wide range of adjustability of the antenna 14 and reflector 81 and the adjustability provided by angularly shiftable support with respect to the pedestal mounting, a high degree of precision in the directive transmission and receiving characteristics of the antenna and reflector system is insured. This makes it possible to adjust and set each of the antenna-reflector combinations on each of the public service boxes with respect to the central station with which the public service box coacts. The numeral 98 as here tofor'e explained designates generally the location of battery housings for low voltage direct current operated boxes, or power line junction boxes for the alternating current operated boxes.

The antenna M and reflector system 8i are so constructed that simultaneous operation of both the radio transmitter and receiver may be effected where the receiver utilizes the reflector as the receiving antenna provided that the receiver is tuned to a difierent frequency than that at which the transmitter operates. To permit such simul taneous operation, I tune the receiving circuit connected to reflector 81 so that it does not respond to the emitted frequency of the transmitting circuit cOnnected to antenna M. The transmitting or directly excited antenna M is designed to function as a director for the purpose of increasing the incoming received signal-to-noise ratio, which action automatically discriminates against interference from other sources, and does actually increase the incoming signal.

The connections or cables 8| and i3! are flexible and allow adjustment of the extensible members H and 85 within the limits required. Telescopically extensible conductors may be provided for adjustment of the feeder conductors over any considerable lengths. The antenna 14 and the parasitic antenna or reflector or receiving antenna 81 are not only variably related in a longitudinal direction but may be oriented by angularly shifting the tubular extensible members H and 85 to desired positions for polarized transmission. That is to say, the structure of my invention is very flexible as it permits the transmitting antenna and its associated reflector to be angularly positioned in any desired relation to the earth and spacially related with respect to each other within wide limits.

While I have described the antenna system of my invention in one of its preferred embodiments, I desire that it be understood that modifications may be made and that no limitations upon my invention are intended other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. In a radio call box system, an antenna support comprising a substantially horizontall extending tubular member, supporting arms telescopically adjustable within said horizontally extending member, an antenna mounted in each of said supporting arms, a connection from each antenna extending through said supporting arms and through said substantially horizontally extending tubular member, and means for selectively fixing the position of said supporting arms with respect to said substantially horizontally extending tubular member.

2. An antenna system comprising a support, a transversely extending tubular member, means for adjustably mounting said tubular member with respect to said support whereby said tubular member may be angularly shifted to various selected angular positions, tubular extensions adjustably mounted in opposite ends of said tubular member, means for maintaining said tubular extensions in predetermined positions with respect to said tubular member, an antenna insulatingly supported by one of said tubular extensions, a reflector insulatingly supported by the other of said tubular extensions, and electrical connections extending from said antenna and said reflector through said tubular extensions and through said tubular member.

3. An antenna system comprising a central support, a transversely extending member angularly shiftable to selected positions with respect to said central support, adjustable members carried by said transversely extending member and extensible and retractable with respect thereto, an antenna supported by one of said adjustable members, and a reflector supported by the other of said adjustable members.

4. An antenna system comprising a central support, a transversely extending member angularly shiftable to selected positions with respect to said central support, adjustable members carried by said transversely extending member and extensible and retractable with respect thereto, an antenna, supported by one of said adjustable members, a reflector supported by the other of said adjustable members, insulation means for isolating said antenna and said reflector from said adjustable members, and electrical connections extending from said antenna and said reflector and electrically insulated from. said adjustable members and said transversely extending member and passing through said support.

5. An antenna system comprising a central support, a transversely extending tubular member carried by said support and selectively adjustable to selected angular positions, tubular extensions slidable longitudinally within said transversely extending tubular member, an antenna insulatingly supported with respect to one of said tubular extensions, a reflector insulatingly supported by the other of said tubular extensions, cables extending through said tubular extensions and through said transversely extending tubular member and through said central support for establishing connectionwith said antenna and said reflector, and means carried by said transversely extending tubular member for securing said tubular extensions in predetermined spacial relation.

6. An antenna system comprising in combination a central support, a transversely extending tubular member carried by said support, means for selectively positioning said transversely extending member in a selected plane with respect to said support, extensible members coacting with opposite ends of said transversely extending member and axially adjustable with respect thereto, an antenna insulatingly supported by one of said extensible members, a reflector insulatingly supported by the other of said extensible members, electrical connections for said antenna and said reflector coextensive'with said extensible members and with said transversely extending member, and means for interengaging the ends of said transversely extending member with said adjustable members for selectively setting said antenna and said reflector in predetermined spacial relation.

7. An antenna comprising in combination, a central support, a transversely extending tubular member selectively adjustable to predetermined angular positions with respect to said central support, extensible tubular members telescopically slidable within each end of said transversely extending tubular member, a conduit extending concentrically within one of said extensible tubular members and through said transversely extending tubular member to said central sup port, the extensible tubular member associated with said conduit being slidable between said transversely extending tubular member and the said conduit concentrically disposed therein, an antenna insulatingly mounted in said last mentioned extensible tubular member and electrically connected through a cable extending through the extensible tubular member and through said conduit and said central support, a reflector insulatingly supported in the other of said extensible tubular members, and a cable electrically connecting said reflector and extending through the respective tubular member and through said transversely extending tubular member and said central support.

8. An antenna comprising in combination, a central support, a transversely disposed tubular member selectively settable in selected positions with respect to said central sup-port, a tubular opening toward said central support and extending axially through one end of said transversely extending tubular member and spacially related thereto, a tubular extensible member 1ongitudinally slidablc between the interior wall of said transversely extending tubular member and the exterior wall of said conduit, antenna insulatr gly supported in said tubular extensible member, a flexible cable electrically connecting said antenna. and extending through said tubular extensible member and through said conduit, a tubular extensible member slidable through the other end of said transversely extending tubular member, a reflector insulatingly supported in said last mentioned tubular extensible member, and a cable connected with said reflector and g through said last mentioned tubular eusibie member and through said transversely ending tubular member to a position adjacent said support.

9. An antenna comprising in combination, a central support, a transversely disposed tubular member selectively settable in selected positions with respect to said central support, a tubular conduit opening toward said central support and extending axially through one end of said transversely extending tubular member and spacially related thereto, a tubular extensible member longitudinally slidable between the interior wall of said transversely extending tubular member and the exterior wall of said conduit, an antenna insulatingly supported in said tubular extensible member, a flexible cable electrically connecting said antenna and extending through said tubular extensible member and through said conduit, a tubular extensible member slidable through the other end or said transversely extending tubular member, a reflector insulatingly supported in said last mentioned tubular extensible member, a cable connected with said reflector and extending through said last mentioned tubular extensible member and through said transversely extending tubular member to a position adjacent said support, and means carried by said transversely extending tubular member for fixing the position of said tubular extensible members with respect thereto.

10. An antenna comprising in combination, a central support, a transversely disposed tubular member selectively settable in selected positions with respect to said central support, a tubular conduit opening toward said central support and extending axially through one end of said transversely extending tubular member and spacially related thereto, a tubular extensible member longitudinally slidable between the interior wall of said transversely extending tubular member and the exterior wall of said conduit, an antenna insulatingly supported in said tubular extensible member, a flexible cable electrically connecting said antenna and extending through said tubular extensible member and through said conduit, a tubular extensible member slidable through the other end of said transversely extending tubular member, a reflector insulatingly supported in said last mentioned tubular extensible member, a cable connected with said reflector and extending through said last mentioned tubular extensible member and through said transversely extending tubular member to a position adjacent said support, and screw threaded means interengaging the ends of said transversely extending member with said tubular extensible members for selectively fixing the spacial relation between sai antenna and said reflector.

11. An antenna comprising a central support, a transversely extending tubular member, means for adjustably mounting said tubular member with respect to said support whereby said tubular member may be set in selected angular positions with respect to said central support, a conduit extending from a position adjacent said central support toward one end of said tubular member and spaced from the interior walls thereof, a tubular extensible member telescopically slidable between said conduit and the interior wall of said transversely extending tubular member, an antenna insulatingly supported in said tubular extensible member, a flexible cable extending from said antenna through said tubular extensible member and through said conduit and terminating in a detachable connector, an electrical connection extending through said central support and terminating in a connector adapted to engage said detachable connector, a tubular extensible member telescopically slidable in the other end of said transversely extending tubular member, a reflector insulatingly supported in said last mentioned tubular extensible member, and a cable extending through said tubular extensible member and through said transversely extending tubular member and through said central sup port.

12. An antenna comprising in combination, a central support, a transversely extending tubular member, means for supporting said tubular member with respect to said central support for adjustment in selected planes, tubular members having elbow portions adjacent one end and a sleeve portion adjacent the other end, the sleeve portions being telescopically slidable within opposite ends of said transversely extending tubular member, screw threaded means carried by the ends of said transversely extending tubular member for clamping the sleeve portions of said tubular extensible members in selected positions, an antenna insulatingly mounted in the elbow portion of one of said tubular members, a reflector insulatingly mounted in the elbow portion of the others of said tubular members, and electrical connections extending from said antenna and said reflector through said tubular members to a position adjacent said central support.

13. An antenna system comprising a support, an antenna member and a reflector member, means for mounting said antenna member for independent spacial and angular adjustments with respect to said support, and means for mounting said reflector member for independent spacial and angular adjustments with respect to said support, said antenna and reflector members being positioned in selected spacial relation and adjusted to a desired angular relationship independently of the selected spacial relation thereof and independently of each other.

LAURENCE G. CUMMING. 

